SwiftUI: Updating Firestore from DetailView - firebase

Question

I am working on incorporating a Firestore repository into a SwiftUI 2 app. The list view loads appropriately, and refreshes automatically when the data in the Firestore collection is changed. A NavigationLink loads the appropriate DetailView correctly. A button on the DetailView is set to change data within the relevant document, and works correctly, but the DetailView page does not refresh with the correct data (it appears correctly when exiting to the list view and returning); likewise the DetailView will not respond to changes to the collection made elsewhere.
I have attempted to use various configurations of ObservedObject and State, but have been unable to get the result intended.
Any help would be appreciated. Snipped Code listed below shows the flow, and uses the status field as an example.
CustomerRepository
class CustomerRepository: ObservableObject {
private let path: String = "customers"
private let store = Firestore.firestore()
#Published var customers: [Customer] = []
private var cancellables: Set<AnyCancellable> = []
init() {
store.collection(path)
.addSnapshotListener { querySnapshot, error in
if let error = error {
print("Error getting customers \(error.localizedDescription)")
return
}
self.customers = querySnapshot?.documents.compactMap { document in
try? document.data(as: Customer.self)
} ?? []
}
}
func update(_ customer: Customer) {
guard let customerID = customer.id else { return }
do {
try store.collection(path).document(customerID).setData(from: customer)
} catch {
fatalError("Unable to update record: \(error.localizedDescription)")
}
}
}
CustomerListViewModel
class CustomerListViewModel: ObservableObject {
#Published var customerViewModels: [CustomerViewModel] = []
private var cancellables: Set<AnyCancellable> = []
#Published var customerRepository = CustomerRepository()
init() {
customerRepository.$customers.map { customers in
customers.map(CustomerViewModel.init)
}
.assign(to: \.customerViewModels, on: self)
.store(in: &cancellables)
}
}
CustomerViewModel
class CustomerViewModel: ObservableObject, Identifiable {
private let customerRepository = CustomerRepository()
#Published var customer: Customer
private var cancellables: Set<AnyCancellable> = []
var id = ""
init(customer: Customer) {
self.customer = customer
$customer
.compactMap { $0.id }
.assign(to: \.id, on: self)
.store(in: &cancellables)
}
func update(customer: Customer) {
customerRepository.update(customer)
}
}
CustomerListView
struct CustomerListView: View {
#ObservedObject var customerListViewModel = CustomerListViewModel()
var body: some View {
NavigationView {
List {
ForEach(customerListViewModel.customerViewModels) { customerViewModel in
NavigationLink(
destination: CustomerDetailView(customerViewModel: customerViewModel)) {
CustomerCell(customerViewModel: customerViewModel)
}
}
}
}
}
}
CustomerDetailView
struct CustomerDetailView: View {
var customerViewModel: CustomerViewModel
var body: some View {
VStack {
Text(customerViewModel.customer.status.description)
}.onTapGesture {
nextTask()
}
}
private func nextTask() {
switch customerViewModel.customer.status {
case .dispatched:
customerViewModel.customer.status = .accepted
...
default:
return
}
update(customer: customerViewModel.customer)
}
func update(customer: Customer) {
customerViewModel.update(customer: customer)
}
}

Answer 1

After some reconfiguring, and the help of this example:
https://peterfriese.dev/swiftui-firebase-update-data/
I was able to solve my issue. Below is a breakdown of the revised code in case it will help others....
CustomerViewModel
class CustomerViewModel: ObservableObject, Identifiable {
#Published var customer: Customer
#Published var modified = false
private var cancellables: Set<AnyCancellable> = []
init(customer: Customer = Customer(status: .new)) {
self.customer = customer
self.$customer
.dropFirst()
.sing { [weak self] customer in
self?.modified = true
}
.store(in: &cancellables)
}
func handleDoneTapped() {
self.updateOrAddCustomer()
}
}
CustomerListView
// Snip to Navigation Link
NavigationLink(
destination: CustomerDetailView(customerViewModel: CustomerViewModel(customer: customerViewModel.customer))) {
CustomerCell(customerViewModel: customerViewModel)
}
CustomerDetailView
struct CustomerDetailView: View {
#ObservedObject var customerViewModel = CustomerViewModel()
var body: some View {
VStack {
Text(customerViewModel.customer.status.description)
}.onTapGesture {
nextTask()
}
}
private func nextTask() {
switch customerViewModel.customer.status {
case .dispatched:
customerViewModel.customer.status = .accepted
...
default:
return
}
update(customer: customerViewModel.customer)
}
func update(customer: Customer) {
customerViewModel.handleDoneTapped()
}
}

Answer 2

Here you need to put the parameters for which values being updated and want the UI to update accordingly:
class CustomerViewModel: ObservableObject, Identifiable {
private let customerRepository = CustomerRepository()
#Published var customer: Customer
private var cancellables: Set<AnyCancellable> = []
var id = ""
var status: StatusEnum
init(customer: Customer) {
self.customer = customer
self.status = customer.status
$customer
.compactMap { $0.status }
.assign(to: \.status, on: self)
.store(in: &cancellables)
$customer
.compactMap { $0.id }
.assign(to: \.id, on: self)
.store(in: &cancellables)
}
func update(customer: Customer) {
customerRepository.update(customer)
}
}
Then, use this new status variable in the view: Text(customerViewModel.status.description).